IB/srp: Fix a comment

The free request list was removed through patch "IB/srp: Use block layer tags".
Hence update a comment that refers to that free request list.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -1112,7 +1112,7 @@ static struct scsi_cmnd *srp_claim_req(struct srp_rdma_ch *ch,
 }
 
 /**
- * srp_free_req() - Unmap data and add request to the free request list.
+ * srp_free_req() - Unmap data and adjust ch->req_lim.
  * @ch:     SRP RDMA channel.
  * @req:    Request to be freed.
  * @scmnd:  SCSI command associated with @req.